1. Fields of the Invention
The present invention relates to a light-emitting diode (LED) chip, especially to an LED chip comprising indirectly overlapped metal layers which are branched and distributed over a surface of the LED chip.
2. Descriptions of Related Art
A light-emitting diode (LED) is a light source made from semiconductor materials such as III-V group of semiconductors including gallium phosphide, gallium arsenide, etc. When a voltage is applied to the semiconductor, electrons and holes meet and recombine under electrode voltage difference. At this moment, the electrons fall to the lower energy level and the energy is released in the form of photons. The electric power is converted to light that is emitted out.
Due to exhaustion of non-renewable resources including coal, natural gas, petroleum, etc, energy saving products also need development besides developing new energy sources to slow down consumption of fossil fuels. Under the pressure of unstable oil prices, countries worldwide are dedicated to develop energy saving products. Thus technologies of light-emitting diode, a so-called green light source, become more mature over time, and the application fields thereof get broader. Right now LED's have been widely used in indicators and display of computer, communication and consumer electronics (3C) products. Along with increasing yield rate of LED's, manufacturing cost per each unit of LED is significantly reduced, prompting adoption of LED as lighting material in various fields.
As mentioned above, since development of high brightness LED has been a research emphasis of manufacturers in most countries, how to further enhance the efficiency of the LED shall be the focus to be stressed for improvement.